51 or 54 ?

upperoilcan

Right,I have been measured for my new bike,I come in right between a 51 and a 54cm question is which one do I go for ? I am 5ft 6 with a 32" inseam,apparently I have a long reach.

I'm lost as to which size to go for,the bike in question is a Cervelo S5,although I am pointing towards the 51.

Help please guys .

Remarkable

I reckon a 51 cm. If you have a long reach, just fit a longer stem.

outcastjack

Cervelo's all seem to have tall head tubes, go down a size.

Monty Dog

At 5ft6 on a 54cm you'd look like you'd stolen your dad's bike ;-)

Stedman

Remarkable wrote:

I reckon a 51 cm. If you have a long reach, just fit a longer stem.

I am also 5'5" and I also have a similar dilemma with the top tube length. Arguably shorter is better with a longer stem, however the critical thing is that there is no toe overlap of the front wheel. It is also worth checking that you can get a large bottle out of the rear bottle holder.

A jump of 3 cm between frame sizes also seems a bit to large and I would also query this.

upperoilcan

Thanks guys,although when I got on the 54 on the turbo it felt fine,I have not tried the 51 so before I stump up the rest of the cash I'm going to get them to get a 51 set up.

I also had not considered the notion of toe overlap !

When did buying a new bike become so difficult ? :P

Jon_1976

I think you need to ride the bike on the road (opposed to using a turbo). Having to balance it whilst riding will give you a better idea whether it's the right size. Agree with the other posters, 51 sounds more suitable.

sloppyschleckonds

Monty Dog wrote:

At 5ft6 on a 54cm you'd look like you'd stolen your dad's bike ;-)

keef66

I'm your height and have the same inside leg. When being fitted for my Racelight Tk they started off with me on a 54 but ended up ordering in a 51 which felt much better and which I subsequently bought. i know it's not the same bike but I'd say if you're stuck between sizes go for the smaller one. Easier to adjust fit with a longer stem / setback post on a smaller frame than to attempt the reverse on a frame that's slightly too big. It'll be lighter too!

Pross

I wouldn't have thought it likely that you have a long reach at 5' 6" with a 32" inseam (unless you have arms like an orangutan), that would appear to be long legged for your height. I'm 6' 2" and only have a 34" inseam :?

keef66

Pross wrote:

I wouldn't have thought it likely that you have a long reach at 5' 6" with a 32" inseam (unless you have arms like an orangutan), that would appear to be long legged for your height. I'm 6' 2" and only have a 34" inseam :?

That's my problem; long legs / short torso, so on the smaller frame with the correct seat height / setabck, I then need a couple of spacers and a flipped stem to bring the bars close enough. On the bigger frame the reach felt just a bit too much of a stretch even with an 80mm stem

diy

Is there much correlation between height and shoe size? I would have thought toe overlap is a factor of the bike geometry rather than sizing for a user? I have pretty massive overlap on my bike, but wouldn't ride anything bigger. Its only really a problem when track standing surely?

upperoilcan

Going to go and try the 51 tomorrow,The guy I spoke to today said the 51 looks a great fit according to my bike fit measurements !!

So the 51 looks favourite as the last thing I want is to look like I'm on my dad's bike at the ripe old age of 39

smoggysteve

I am 5'6" and ride a 53cm I would recommend of the 2 you go for the smaller. you can always make a slightly smaller frame fit with longer stems etc but a too big frame will remain too big.

I only ride 53 cos I am closer to that than a 50 as far as Bianchi frames go but any bigger I would feel I would be overstretching. Toe overlap can be remedied with crank arm length. I went down to 165cm crank from a 172.5cm It feels a lot more comfortable and I am no longer likely to clip to front wheel.

sloppyschleckonds

Toe overlap isn't the worst thing in the world, unless you fall off and die.

smoggysteve

SloppySchleckonds wrote:

Toe overlap isn't the worst thing in the world, unless you fall off and die.

you could slice the end of your foot off on a sharp aero bladed spoke and bleed out through your big toe.

upperoilcan

Well here I am waiting for my new bike to be ready,I have gone for the 54 as the stack height of the 51 made it look like a chopper ! I now only have a 10mm stack and the saddle to bar drop is perfect ! Had to put the sizing thing to bed though !

Remarkable

upperoilcan wrote:

Well here I am waiting for my new bike to be ready,I have gone for the 54 as the stack height of the 51 made it look like a chopper ! I now only have a 10mm stack and the saddle to bar drop is perfect ! Had to put the sizing thing to bed though !

Seriously, 54 is too large for your height. If the head tube is too short on the 51, you should consider a different bike.

Grill

Remarkable wrote:

upperoilcan wrote:

Well here I am waiting for my new bike to be ready,I have gone for the 54 as the stack height of the 51 made it look like a chopper ! I now only have a 10mm stack and the saddle to bar drop is perfect ! Had to put the sizing thing to bed though !

Seriously, 54 is too large for your height. If the head tube is too short on the 51, you should consider a different bike.

This. I'm almost 6 inches taller than you and that's what I would ride.

upperoilcan

Bit late mate,bought and paid for,pics are in the "Your road bikes section"

anonmouse

A bit late but I am almost the same size and here is my old 51cm S5 versus a 54cm R3.





Both set up with Retul info.